AS & Sacroiliitis

Dr Deane reviews a study that evaluated the Assessment of SpondyloArthritis international Society (ASAS) in a cohort of patients with persistent low back pain.

Sacroiliitis is the hallmark of Ankylosing Spondylitis, now termed as Axial Spondyloarthritis. It is therefore important to know what makes for the diagnosis, so that patients can avail themselves to the emerging and effective treatments.

Increased use of MRI for diagnosis of spondyloarthritis (SpA) in the last two decades has led to earlier diagnoses and gradual incorporation of MRI into the…

Merely having radiographic (XRay) evidence of sacroiliitis may not necessarily justify treatment, be it with NSAIDs/coxibs or biologics (anti-TNF/IL17). The sacroiliitis should also be determined to be “active”, so as not to escalate immunosuppression unnecessarily. This is where MRI comes in, with subchondral Bone Marrow Edema (BME) being a defining feature.

Differentials, such as Osteoarthritis, Gout and Infections (eg TB), also need to be excluded, so that the right therapy is given.

Defining active sacroiliitis on MRI for classification of axial spondyloarthritis: update by the ASAS MRI working group

 Figure 1